BobH said:
Things have improved now, as I did some searching and found that I
should have disabled write caching for my SSD drive, which I did
initially, but forgot to do a couple of things since the re install.
Earlier, when a program I use to catalogue my CDs/DVD's took something
like 1 hour 20 minutes to read all the data of about 4gb on a DVD, but
now it can be done in much less than 1 hour, say about 45 minutes.
So that seems to be about normal now for me.
Thanks for all the replies and suggestions
There is actually a benchmark for optical drives.
It's a freebie.
The following picture, shows two versions of the program,
The current version is called Nero DiscSpeed.
http://img163.imageshack.us/img163/1669/cdbench.gif
You can get a copy of Nero DiscSpeed here.
http://www.nero.com/enu/downloads/index.php
(DiscSpeed - 29.5MB)
When I installed that in Windows 8, it insisted that I install
..NET 3.5. So the latest version is a bit of a pain, compared
to previous ones that didn't have quite as many dependencies.
(If you're prompted at runtime to "turn on Autoruns", just
say no, as I think that's so they can pop up advertising in
your face
There is no reason for *anything* to Autorun in that
program. It is just a benchmark, not a home entertainment system.)
*******
The right hand vertical axis, is the speed in megabytes per second.
The disc reads from the hub (small diameter) to the outside edge
(big diameter), and in this case, the spindle spins at a relatively
constant speed. That's called CAV as far as I know. The data rate
increases because of the diameter of the media the head is over
at the moment. The read path is a spiral.
In my benchmark, the disc playback ends while it was transferring
at a bit more than 12MB/sec.
The reason those were photographed half finished, is the results get
blanked out if I let it run to completion. The seek tests appear
to be a total fabrication (because, for one thing, the drive doesn't
stay spinning at high speed, which invalidates the attempt to read).
But at least the sustained transfer curve has some value. The stuff in
the left column of numbers is trustworthy, while the right
column is less so. The seek time should be down around 100 milliseconds
or so.
My optical drive is connected via USB2 (30MB/sec max), and so slightly
more than 12MB/sec does not tax it.
When a storage device is connected to SATA or IDE, it can operate
in DMA mode or polled (PIO) mode. PIO, since it's done by the CPU,
can be quite slow. Windows will "gear down" to PIO mode, if
excessive errors are seen on the cabling. The theory goes, that
slowing the transfer, will somehow improve the error rate, which
is why they did it.
If you see a curve, chances are all is well. If you see a "flat line",
and it's significantly slower, it could be the drive is not in the
right mode for best results.
Notice there are very few "spikes" in my graphs, implying the error
rate isn't too bad. Errors are definitely present, but they're not
an issue until they're in the "thousands" rather than in the "tens"
of errors. Once you get to the "thousands of errors" level, things
start to slow down, or you see a downward speed spike in the scan.
The access time (head movement) on optical discs is quite slow. The CD drive
can move its head around (for random file access), in about 70% of the
time that it takes a DVD or BluRay drive. It's one reason to continue
to try to install software from an actual CD drive. Random access will
cause the effective transfer rate to slow to a crawl. A person
designing an installer CD, the idea is, they're supposed to arrange the
files for smooth continuous transfer, rather than make the head jump all
over the place. So if it seems slow, that's another reason - less than
optimal file size and placement.
Post a link to a picture of your benchmark run, for comments.
Paul
